Apparatus for recovering potassium salts from cement-kilns.



H. BLUMENBERG, In.

RING POTASSIUM SALTS APPLICATION mm MAR. 15, m

APPARATUS FOR REC-0V5 mom CEMENT- muvs.

Pa t nted Mar. 4, 191%).

Ivnren tor; fie-wry fllumenberfq, Jr

UNITED STATES HENRY BLUMENBEBG, JR., 0F 0R0 GRANDE, CALIFORNIA.

APPARATUS FOR RECOVERING POTASSIUM SALTS FROM CEMENT-KILNS.

Specification of Letters Patent.

Patented Mar. 4, 1919.

Application filed March 15. 1918. Serial No. 222,766.

To all whom it may conccrn:

Be it. known that I. IlENRY BLUMENBERG, Jr., a citizen of the United States. residing at Oro (lrande. in the county of San Bernardino and State of California, have invented new and useful Improvements in Apparatus for Recovering Potassium Salts from Cement-Kilns, of which the following is a specification.

My invention relates to an apparatus for recovering potassium compounds carried by hot gases, and especially gases from a re mcnt kiln.

Potassium salts are produced nowadays as a by-product of cement kilns. Potassium containing materials, such as feldspar and the like are used in the manufacture of cement. The high temperature of the cement kilns volatilizcs the potassium compounds which, tnixed with cement dust, is carried off by the hot waste gases.

It is an object of the present invention to provide a simple vct ctlicieut apparatus for recovering potassium compounds from said gases,

My invention consists in the combination and arrangement of the parts of the apparatus hereinafter described and claimed.

In the accompanying drawings which form a part of this specification, l have illustrated the apparatus. and in which:

Figure 1 is a vertical section thcrcof.

Fig. 2 is a top plan view thereof, some parts being shown as broken away, for purposes of clearer illustration.

10 indicates the upper end of a rotary cement kiln which terminates in the lower end of a precipitating tower 11. A conduit 12 conducts the gases from the upper end of tower 11 to the lower end of tower 13. A conduit 14 conducts the gases from tower 13 to a centrifugal fan or blower 15 which forces the same into the lower end of the precipitating tower 16. Another conduit 17 conducts the gases from the u pcr end of the lower 16 to the lower end 0 a tower i8. 41 is a gas outlet leading from the top of tower 18.

These towers may be of any suitable height. I have found that towers about 15 feet high give excellent results. They are circular in cross section, though they may be of any preferred shape and about 8 feet in diameter. Each tower is provided with a series of perforated battle plates 19 horizoir tally arranged. These battle plates are provided with perforations Qtlot one-half inch in diameter and about one inch apart. A centrifugal pump 21 circulates a precipitating liquid which may be water or an aqueous mixture of compounds such as alkaline mixtures containing sodium. potassium. aluminum silicates. or a metal nitrate solution, or calcium sulfate and the like. suitable for collcctin the cement dust and potassium com poum 3 carried by the gases through pipe 22. leading to the top of the prctipitatiug towers 11 and 13. Valved pipes 2% terminating in spray nozzlesl -l in the tops of the.

towers 11 and 13 cause the liquid to How down the towers and through. the baliie plates in minute streams. The greater )0r tion of the potassium (Ollllullllltls (1x 0) and practically all the cement dust. of the hot. gases are precipitated by the liquid and form a magma or slurry which is collected in the bottoms of the towers 1i and 13. Untlets :25 lead from the ottom of the towers 11 and 13 to a tank 26 conunupleating with pipe 27 with the centrifugal pump :31.

A centrifugal pump 28 suppl es towers 1f) and 18 with a precipitating: liouid by means of pipe 29 and branch pipes P-tl terminating: in spray nozzles 31 in the cups of said towers. Outlets 3:! at the bottom of said towers conduct the liquid and precipitated matter to a collecting tank 3 5 communicat ing with pipc ill with pum 12*. A pipe 33 leads from pipe :22 to a. fil er press 736. 37 is a. valve in pipe 35 andpls is a valve in pipe 22. A valved pipe till l ads from pipe 29 which latter is provided with a. valve 40.

In the operation of the apparatus. the hot gases coming from the cement lailn pass through the towers 11 and l?) in series and practically all of the cement dust is pro cipitated therein. The. gases are cooled from a temperature of approvimatcly 120W l .to about 212 I. and saturated with steam. It should hcnotcd that the centrifugal pump or blower 15 silt'lis the gas th n {In} tow el's 11 and 13 and forces them through tmw ers 16 and 18 where the remainin portion i the potassium compounds are precipitated by the water flowing down the towers ill and 1H. robably onc quat'tcr of the potassium compouuds are carried in the gases over into the towers Ill and 18. The slurry collected in towers l1 and '1? i pumped to filter press 343 which separates the soluble potas- SiIlDl salts from the insoluble lime salts and the like. If desired, the slurry may be dried without separating potassium compounds therefrom. The rumor part of the dried slurry consists of calcium carbonate and calcium oxid which are valuable fertilizers, in conjunction with potassium compounds contained in the slurry.

The liquid derived from towers 16 and 18 is practically free from cement material, and it is unnecessary to filter ress the same. The liquid may be pumped t rough a pipe 39 after closing valve 10 in pipe 29, to any convenient apparatus where the same is evaporated to dryness.

While I have shown only two precipitating towers 11 and 13 for collecting the cement dust and only two towers 16 and 18 for recovering the potassium not precipitated in the first two towers, it wiil be understood that ahysuitable number may be employed.

The advantage of the present apparatus over the one shown in my copending application for a processof recovering potassium and apparatus therefor Seria No. 214212, filed January 28th, 1918, is the provision of a precipitating tower extracting otassium compounds after the cement dust has been precipitated in the first set of towers 11 and 13, and a separate circulating system and pump keeping the concentrates which contain the potassium compounds, with practically no cement dust derived from towers 16 and 18, separate, thereby avoiding the expense of filter pressing all the concentrates.

The process described but not claimed in this application is made the subject of a copending application for process of recovering potassium compounds from waste gases of cement kilns and the like, filed March 15, 1918, Serial No. 222767.

I claim:

An apparatus for recovering potassium compounds carried in suspension by hot ases and mixed with other solids, comprismg a precipitating chamber through which the gases are caused to circulate, means for causing a precipitating li uid to come in intimate contact with sai gases in said chamber, whereby a large ortion of the potassium compounds and substantially all the other solids are precipitated, means for separating potassium compounds from the precipitated matter, means for conducting the ases from said chamber into a second precipitating chamber, means for causing a precipitating liquid to come in intimate contact with said gases in said second chamber, whereby substantially all the remaining potassium compounds are precipitated, and means for conveying the potassium compound containing liquid from said second chamber inde endently of the liquid mixture collected in the first chamber.

In testimony whereof I have signed my name to this specification.

HENRY BLUMENBERG, J n. 

